Reversible Adhesive Film with Ultralow Dielectric Loss in High Frequency via Surface Anchoring of Catechol

Abstract

Debonding of the dielectric adhesive material will make the high-frequency communication equipment unusable, leading to resource wasting and electronic waste. Reversible adhesive is an ideal strategy to realize the reuse of debonding devices, but the low dielectric loss requirement of the dielectric adhesive materials in high-frequency devices limits its development. Here, the surface anchoring design of catechol was proposed to prepare a reversible adhesive film with ultralow dielectric loss in high frequency. The catechol structure was linked to the end of polybutadiene (PB) macromolecule to synthesize catechol-terminated PB (PB-D). The PB-based adhesive film (PB-F) with ultralow dielectric loss was used as the base film, and then PB-D was sprayed on PB-F to form a thin layer. In the subsequent curing process, the catechol group on the surface of PB-F could be anchored by the cross-linking reaction between the heterogeneous PB segments. The surface modification transforms the interface debonding between PB-F and copper foil into cohesive failure within the PB-D layer, showing a strong adhesion of more than 1.1 N/mm. More importantly, relying on the reversible hydrogen bonding of catechol structures, the debonding material can regain stable bonding in a mild way. Because the catechol group is only distributed on the film surface, the reversible adhesive film kept an ultralow dielectric loss (D_f = 2.5–2.9 × 10^–3) at 10 GHz. In this work, an ultralow dielectric loss and reversible adhesive film with commercial prospects was prepared for the first time, which is expected to be used for simple recovery of communication substrate bonding failure.